"Phorm has agreed to allow an independent software expert to inspect its source code as it continues to battle the firestorm provoked by agreements with BT, Virgin Media and Carphone Warehouse to let it build profiles of their broadband customers' web browsing."
http://www.theregister.co.uk/2008/03/19/phorm_8020_pi/
As ever, The Register's thoughts and the subsequent comments are worth reading.